31P NMR of tissue phospholipids: competition for Mg2+, Ca2+, Na+ and K+ cations.
31P NMR of tissue phospholipids: competition for Mg2+, Ca2+, Na+ and K+ cations.
复制标题
组织磷脂的 31P NMR：Mg2、Ca2、Na 和 K 阳离子的竞争。
作者：
Merchant,TE;Glonek,T
将磷脂酰胆碱（PC）、磷脂酰乙醇胺（PE）、乙醇胺缩醛磷脂（EPLAS）、鞘磷脂（SPH）、磷脂酰肌醇（PI）、磷脂酰丝氨酸（PS）、心磷脂（CL）、磷脂酰甘油（PG）和磷脂酸（PA）分散在Cs（乙二胺四乙酸）洗涤的氯仿/甲醇溶液中，记录高分辨~（31）P核磁共振谱。在单独的滴定实验中，将Mg 2+和Ca 2+加入分散的磷脂混合物中，以测定每种磷脂对每种加入的阳离子的相对相互作用电位。通过31 P化学位移变化、信号增宽、信号淬灭或这些的组合来指示阳离子与单个磷脂的缔合。滴定表明，CL具有最高的，PA的次高，镁离子的相互作用潜力。与此相反，PS和PA有最高的，CL次高，相互作用的潜力Ca 2+。仅考虑与Ca 2+离子的相互作用，磷脂可分为三个不同的组：PS和PA（高相互作用潜力）; CL、PI和PG（中等相互作用潜力）;以及EPLAS、PE、SPH和PC（基本上没有相互作用潜力）。两种磷脂的相互作用潜力最小的碱土金属阳离子的PC和SPH。Na+和K+离子与PA，CL，PI和PG的相互作用是独特的，并导致相对于Cs+离子存在下的化学位移的正化学位移变化。相对于Cs+和K+离子，Na+离子存在下的化学位移按PA>CL>PI> PG的顺序被去屏蔽δ> 0.1ppm。
Phosphatidylcholine (PC), phosphatidylethanolamine (PE), ethanolamine plasmalogen (EPLAS), sphingomyelin (SPH), phosphatidylinositol (PI), phosphatidylserine (PS), cardiolipin (CL), phosphatidylglycerol (PG) and phosphatidic acid (PA) were dispersed together in Cs(ethylenedinitrilo)tetraacetic acid-scrubbed chloroform/methanol solution, and high resolution31P nuclear magnetic resonance spectra were recorded. In separate titration experiments, Mg2+and Ca2+were added to the dispersed phospholipid mixture to determine the relative interaction potentials of each of the phospholipids for each of the added cations. The association of cations with individual phospholipids was indicated by31P chemical-shift changes, signal broadening, signal quenching or a combination of these. The titrations revealed that CL had the highest, and PA the next highest, interaction potential for Mg2+cations. In contrast, PS and PA had the highest, and CL the next highest, interaction potential for Ca2+. Considering only interactions with Ca2+ions, the phospholipids can be divided into three distinct groups: PS and PA (high interaction potential); CL, PI and PG (intermediate interaction potential); and EPLAS, PE, SPH and PC (essentially no interaction potential). The two phospholipids with the least interaction potential for either of the alkaline-earth cations were PC and SPH. Na+and K+ion interactions with PA, CL, PI and PG were unique and resulted in positive chemical-shift changes relative to the chemical shifts in the presence of Cs+ions. Relative to both Cs+and K+ions, chemical shifts in the presence of Na+ions were deshielded δ>0.1 ppm in the order PA>CL>PI>PG.